Digital abacus



FIG. 1 is a top, front perspective view of a digital abacus showing ournew design;

FIG. 2 is a top plan view of the digital abacus shown in FIG. 1, thebottom view being substantially identical thereto;

FIG. 3 is a side view of the digital abacus shown in FIG. 1, theopposite side being substantially identical thereto; and,

FIG. 4 is an end view of the digital abacus shown in FIG. 1, drawn on anenlarged scale, the opposite side being substantially identical thereto.

The ornamental design for a digital abacus, as shown and described.